The boss of WA's child protection agency has had to defend his department after 16 reports of child abuse in State care in 2011-12 - the most in almost a decade.
The previous year there were just two reported cases.
Department for Child Protection director-general Terry Murphy told a parliamentary committee yesterday the abuse represented a "significant increase" compared with previous years and was on par with the level recorded in 2003-2004.
Mr Murphy said the spike could be because of the increasing vigilance of department staff and a low threshold for what constituted abuse.
He said one child was sexually abused and the grandfather - the approved respite carer - was charged. Eleven of the children were in the care of relatives when abused, four were in general foster care and one was in a residential facility in the Northern Territory, which has been closed.
Shadow child protection minister Sue Ellery said the rise was alarming and the number had not been this high in more than seven years. The average number of cases was two or three a year.
"Children in the care of the department have already been taken into care because they have suffered some kind of harm," she said.
"For them to be further abused when they're supposed to be kept safe is a shocking indictment."
Ms Ellery accused the department of trying to hide the rise by not including the number of children abused in State care in its annual report, as it had previously.
The committee was also told the number of department staff who faced substantiated misconduct allegations in 2011-2012 rose sharply from the previous year.
In 2011-2012, 56 allegations of misconduct were investigated with 22 substantiated, up from 42 allegations and five substantiated cases the previous year.
"This is a dramatic increase and is so alarming because these people are employed to look after children who are in the department's care," Ms Ellery said.
Mr Murphy said most misconduct allegations were for "unprofessional communication" and "inappropriate physical contact" but the department set the bar low for misconduct and often it would not constitute improper behaviour in an "everyday home".
He said the rise was because of stricter rules around the identification and reporting of misconduct, rather than actual cases.